I need help with cancelling buy or sell limit for specific currencies pairs if the opposite order limit touched.

 
I need help with cancelling buy or sell limit for specific currencies pairs if the opposite order limit touched.

example:


I have 10 pending trades


buy limit and sell limit for eurusd

buy limit and sell limit for gbpjpy and so on.....



if the sell limit for eurusd touched then cancel buy limit for eurusd only


i would like it as an expert advisor, I dont know how to program


please help